David Rainey, a former BP vice president during the Deepwater Horizon oil rig explosion, leaves Federal Court after being arraigned on obstruction of a federal investigation in New Orleans in November 2012. (AP Photo/Matthew Hinton)

In court papers filed this week, David Rainey’s attorneys say the government’s challenge of Brian Heberlig’s representation of Rainey should be thrown out.

“What the task force seeks threatens Mr. Rainey’s constitutional right to counsel of choice and undermines the protections of the work-product doctrine,” the attorneys wrote in the filing in federal court in New Orleans.

Federal prosecutors have said they may call Heberlig as a witness at trial to discuss statements Rainey made during a private meeting with prosecutors before Rainey was charged.

Alleged statements during that 2011 meeting are the basis of one of the two charges Rainey faces in the case.

The prosecutors have said that if Heberlig were called and his testimony was adverse to Rainey, that would create a conflict in his representation of Rainey.

In their motion challenging Heberlig’s representation, prosecutors have asked a judge to order the defense to turn over certain information to help determine whether Rainey can waive the conflict of interest or if further measures need to be taken, up to and potentially including removing Heberlig from the case.

The government wants the defense to detail in advance the expected testimony of another attorney on the defense team, David Fragale, who also was at the meeting in question. Fragale isn’t expected to be a lead attorney at trial, so the government isn’t challenging his representation of Rainey.

The government also wants the defense to declare whether Heberlig has the potential to corroborate or contradict Fragale’s testimony.

In the defense response filed Tuesday, Rainey’s attorneys said they shouldn’t have to turn over anything. They said prosecutors did not object to Heberlig’s representation of Rainey for some two years after the meeting in question. The defense suggested the government’s motion is part of a strategy to create a conflict where there is none just to remove Heberlig.

“The task force’s rank speculation that Mr. Heberlig’s recollection could differ materially from Mr. Fragale’s, and that it might differ in a way helpful to the task force, does not change the analysis,” the attorneys said.

They added, “The task force is not entitled to fish through attorney work product in an attempt to find a conflict.”

The government motion says the meeting in question occurred on April 6, 2011. Prosecutors say Rainey falsely stated that he had calculated a flow rate estimate for BP’s Macondo well of roughly 5,000 barrels of oil per day before seeing the government’s similar estimate at the time.

The actual total, based on the government’s current estimate, was roughly 48,000 barrels of oil per day.

Rainey has pleaded not guilty to charges of obstruction of a congressional investigation and making a false statement to federal law enforcement officials. His trial is scheduled for October.

Rainey no longer works for BP. He is now president of exploration for BHP Billiton.

A former BP engineer and two BP well-site leaders also face criminal charges in the Gulf oil spill case.